Studies will be continued on the purification of the androgen receptor protein. Androgen receptor interactions in nuclei will be investigated with respect to binding to nuclear components. Nuclear membrane, chromatin and extra-chromatin components will be investigated. Relative binding of testosterone and dihydrotestosterone receptor complexes will be compared. Work will continue on the isolation and characterization of major secretory proteins of the male reproductive tract. Messenger RNAs will be purified and cDNAs synthesized in preparation for studies on hormonal regulation of gene transcription and mRNA translation. Studies on the hormonal control of Sertoli cell function will be continued using ABP radioimmunoassay and immunocytochemical methods for the intracellular localization of ABP.